My Experience
Several years ago, my wife and I used their "Cruising Out Of Arizona" special to take a 27 foot MH to Seattle from Arizona. The refrigerator died overnight and they gave us the option of getting it repaired or buying a cooler and ice. No discount for your time spent at repair facility! So, we bought a decent cooler and ice. Afterwards we turned in our receipts and were fully reimbursed no problem.
Be aware that your ACTUAL rental is shorter than you think. You can't pick it up until the afternoon and you might have to wait your turn behind other renters. The paperwork, walk through, instructions, inspection, provisioning etc can eat up a couple hours. Your first day is essentially shot. Same goes with your last day. You have to return it, clean inside, in the morning, with full gas and empty waste tanks. Severe penalties apply for each hour late. So, a 8 day 7night rental that seems so long is really 6 full days on the road!
They do give you plenty of free miles, but not enough time to enjoy them in my opinion. If you want to spend two days in one or two locations, you'll have very very long drives the other days. We paid full price for two extra days and still felt rushed.
All in all, we really enjoyed the trip, especially at $25 per day for most of them.
An alternative, that we've also used is Camping World. Their specials are found at rvrental.com though. The bad thing is that they only give you 100 miles per day but they often give the discount rate for several weeks, so you don't dont feel rushed. Their units also come with slides, unlike any of Cruise America's.
You can plan a pleasant and cheap vacation using either company, but make sure to do your homework to ensure that their rental specifics fit your vacation plans.